hello matmuchrapna, the transparency landed in the early firefox nightly build (36), while the firefox developer edition is currently at version 35 - you will see this change in the dev edition in a couple of weeks...

So Nightly is not the same as the Developer Edition?

Where I can download both of them?

firefox has 4 channels, that are released in a schedule every six weeks. those are (currently): nightly (36), developer edition (35), beta (34), release (33).

in the nightly channel most of the development is done & this is the place where most new features land first, so it should be considered as an early alpha version which is far less stable than the other channels.

https://www.mozilla.org/firefox/developer/ https://nightly.mozilla.org/

Thank you